1. Technical Field
The present invention relates to a single-substrate processing method and apparatus for performing a semiconductor process, such as film-formation, etching, oxidation, diffusion, or annealing. The term “semiconductor process” used herein includes various kinds of processes which are performed to manufacture a semiconductor device or a structure having wiring layers, electrodes, and the like to be connected to a semiconductor device, on a target substrate, such as a semiconductor wafer or an LCD substrate, by forming semiconductor layers, insulating layers, and conductive layers in predetermined patterns on the target substrate.
2. Background Art
In the process of manufacturing semiconductor devices, various semiconductor processing apparatuses are used for performing processes, such as film-formation, etching, oxidation, diffusion, and annealing, on a target substrate, such as a semiconductor wafer. A single-substrate processing apparatus for processing wafers one by one is known as a semiconductor processing apparatus of this kind.
FIG. 6 is a schematic structural view showing a conventional single-substrate processing apparatus for a semiconductor process. As shown in FIG. 6, this apparatus includes a process chamber 2, which can be vacuum-exhausted. A worktable 4 is disposed within the process chamber 2, for placing a semiconductor wafer W thereon. A showerhead 6 is disposed on the ceiling of the process chamber 2, for supplying a process gas. An exhaust line 7 is connected to the bottom of the process chamber 2, for exhausting the interior of the process chamber 2. A plurality of heating lamps (heater) 8 are disposed below the bottom of the process chamber 2, as a temperature control.
Thermic rays emitted from the heating lamps 8 are transmitted through a transmission window 9 formed of, e.g., quartz, and disposed in the bottom, and then the rays are radiated on the worktable 4. With the energy of the thermic rays, the wafer W is heated to a high temperature to perform a process at a predetermined temperature. The worktable 4 is provided with a temperature measuring device, such as a thermocouple 10. The temperature measured by the thermocouple 10 is transmitted to a temperature control section 11. The temperature control section 11 controls applied power to the heating lamps 8, on the basis of temperature measured by the thermocouple 10. As a consequence, the worktable 4 can be continuously maintained at a predetermined temperature.
The apparatus shown in FIG. 6 heats the worktable 4, thereby indirectly heating a wafer W placed thereon. Since there is a small thermal resistance between the wafer W and worktable 4, a temperature difference inevitably exists between the two members. Accordingly, the temperature of the worktable 4 is controlled in consideration of the temperature difference to heat the wafer W to a predetermined temperature.